TRANSMUTABLE. 51 



Darwin's variations must have either taken this 

 course, or he must have disproved the maxim he 

 is so anxious to support. "Natura non facit 

 sal turn." 



But Mr. Darwin is himself very explicit upon 

 the subject. u lf it could be demonstrated that 

 any complex organ existed which could next pos- 

 sibly have been formed by numerous successive 

 slight modifications, my theory would absolutely 

 break down." (Page 189, Chapter YL) 



But then seeing the difficulty, he argues it 

 thus, "If we look to an organ common to all 

 the members of a large class, in this case the 

 organ must have been first formed at an ex- 

 tremely remote period, since which all the mem- 

 bers of the class have been developed; and in 

 order to discover the early transitional grades 

 through which the organ has passed, we should 

 have to look to very ancient ancestral forms, 

 long since extinct." (Pages 189-90.) 



And then he goes at once into what he calls 

 the proof of transition in organs, by adducing 

 the homology of the swim bladder in fishes and 

 lung of mammal; and because some fishes aerate 

 part of the blood in the swim bladder as well 

 as the lung, Mr. D. considers he has adduced an 

 instance of how the minor organism may be 

 transmuted into the major, or, in his own words, 

 u there seems to me to be no great difficulty in 

 believing that natural selection has actually 

 converted the swim bladder into a lung, or organ 

 used exclusively for respiration." (Page 191.) 



